Fe—Ni alloys represented by Invar alloy, Kovar alloy and perm-alloy, are widely accepted for their advantages of the performance in thermal expansion and soft magnetic properties. In recent years, following the development of technologies in the microelectronics industry, the advantages of Fe—Ni alloy materials in nature such as lead-free solder-ability and interface reaction rate are gradually being recognized by researchers and investigated in depth. The related achievements are being published continuously from the studies. A large amount of study data shows that Fe—Ni thin film materials hold good solder-ability and slow interface reaction rate. It lays the foundation for the wide application of Fe—Ni thin film materials in the micro-electronics industry. Nevertheless, if used as magnetic core of inductor devices in chips, the existing Fe—Ni thin film materials tend to consume energy in their high-frequency application, which results in a rapid decrease of inductance and lost advantages in power conversion. Therefore, more research is urged to carry out further studies in order to improve the performance of materials.
Compared with the preparation methods such as magnetron sputtering, chemical vapor deposition (CVD) and atom layer deposition frequently used in the microelectronics industry, the electroplating method is preferred in the industries due to its advantages of low upfront investment on equipment, easy and feasible operation, short cycle of material preparation, high efficiency, low operation cost, etc.